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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let age = 22;
        console.log(typeof age);  //number
        // 1.number 转化为字符串
        age = age.toString();
        console.log(typeof age); //string
        // 2.强化转化
        let score = String(100);
        console.log(typeof score); //string
        //  3. prompt()接收的数据作为字符串
        let year = prompt('请输入你的出生日期');
        console.log(typeof year); //string 
    </script>
</body>
</html>